Snap-together coupling of elements is used extensively in the conventional fabrication of plastic assemblies in which elastic and dynamic performance requirements may not be high. In conventional snap-together couplings, there are design clearances that allow elements to be coupled. The required design clearances in such conventional snap-fit couplings may create rattles and movement in the coupled assembly, and may prevent the creation of strong couplings.
Shrink-fit couplings are used in engineering practice to fasten metal elements together. Shrink-fitting is generally accomplished by first elevating the temperature of one element to increase its physical dimensions, then fitting a second element inside the first, and finally cooling the assembly to shrink the first element. The second element becomes bound by friction inside the first. This type of conventional technique is used in a variety of mechanical systems, including gear and propeller placement on shafts, and in toolholders for machine tools. Shrink fitting is normally a permanent method by which to couple elements, and is therefore usually not reversible.
There exists a need for a method to couple elements to create strong assemblies with no or minimal play or clearance between the elements, yet using a minimal amount of time, effort, and energy to perform the coupling.